US869314A - Resistance unit. - Google Patents

Description

No. 859,314.- PATEN'IED 0012.29', 1907.

o. MAUMILLAN. RESISTANCE UNIT.

EPE-Immun FILED 111:0.'1. 1905.

fz// iig/ww f f III/IIE l' lll/"mjy 1 mimi" WITNESSES. INVLNTDR.

- l EAMPUELLMAEMILLAN- UNITED sTATEs EETENT oEEIoE.

CAMPBELL MACMILLAN, OF SCI'IENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

RESISTANCE UNIT.

No. 869,314. Specification of Letters Patent. Patented Oct. 29, 1907.

Apiilontinn filed December ll 1905. Serial Nn. 289,931.

T all U-hOm l mail concern: matcrial having a negative temperature coefficient and Be it known that l. CAMPBELL M ACMILLAN, a subject Commonly known is Seihi-@ducing resistance, Since of the King of (lrrat Britain. rtsiding at Schenectady, its SpeciiiC resistance decimiss Wich increase of mhh county of Schenectady. State of New York, have inpeinture. Tim iiiii-ticiihii. mateijui used constitutes vented certain new and useful linprovcnicnts in Ri ,i0 Pmi of my iiiviiii011 and may be of any of the W@11 6() sistamcoUnits. of which the following isaspecifcation. known substancias imvimor the necessary pr0perties- This invention rulalis to resist-anc(l units for electric Among these Substances might be mentioned magnetcircuits and has for its object tho provision of a unil, of it@ and Siiimii, the hihihi. heini., either in the Cast or this character which will bc chrap and simple of con- ,hohied h,i.iii rphis Stick 0f mami-ini I have Shown for struction. give a iride range of variation, which will iihrhoseshi iihisimtiiiii iii the Shape if a tube'pmvided 65 withstand high tempi-mtime and at the saine timal will with a spimi groove 2 although it is obvious it is not hilv@ SUlClP-N Uu'f'llmlll Strength lo "Undlr it sul essential that this groove he on the inside of the tube, mill dumlilor in fact, that it be grooved at all so long as it accom- Mfr" Sllf'lllmlly my ln\"("llllm has for lts "ll-lufL lll@ plishes the object of having the turns of the conductor A Y l5 production oi a resistance unit having a m-gative tomin Contact with the resistance stick Within the 7() poraturc coeilicicnt and which is somt-timos known as groove 2 is i Spiral conductor 3 Which iS preferably a re soli-reducing resistance. Rrsistancc units of this type Sishm Conductor Capable of Wii-hshindii'ig a comparaare not new in the art but those produced up to tinl tively high iiipciiitum This ciinductor may be PTCS'JU tlm@ 'have Uslmlly had Certain dlsilllflllllgl wound on a mandrel and the material molded around This typo of rr sistancc has been made both in the forni it or any desired iiiemis may be employed for bringing 75 0f S'Ck ICSSmUC@ and also l thelorm 0f l flexible con' the conductor into intimate relation with the material. ductor such as Wire or ribbon. Both the ficxihlc con- The ends of the mbe are Closed by means of Caps 4 and ductor and the stick resistance have their advantages 5 Whidi may he Oibeii 0i. any desired material Secured and special uses and it is the object o my invention to to the ends of tube- The ends 0f the Conductor gr combine these two forms into an automatic Self-rcducbrought out ai, Opposite ends of the tube through 80 lng resistance' l these caps secured thereto by means of bolts 6 and 7 l Carrying Out my lmfntlon I provide a flexible which form terminals for connecting the unit in circuit. conductor, preferably in the orm'oi a spiral, and means It Win be geen that when a Current is passed through f or supporting the Same in COMMt Wtha resistance this unititS-rosistancerwll be practially that o th, material llavlngahlgll negativ@ temperatur@ Coelllclltmetallic conductor which may be adjusted as desired. 85 I At Stm-ting, when the unit is cold, the'rcsistance of tho As the conductor heats it raises the temperature of the unit l5 Practically tlltlol the Spiral" AS the unit heats surrounding material which gradually reduces in resist- UP, hOWGVT, the TGSSUMICO 0f th@ material'in contact ance and short-circuits the turns ofthe conductor. The with the-conductor dcCrGaSPS and gradually short-cirnal resistance of the unit will be that of the surround- 35 CUS thc turns 0f the ConduC'OI S 21ste automatically ing material at the temperature at which it is desired v 90 reduce the resistance of the' I Hlit A uuit of this charthat it shall be used. The cross-section of the sur:4 actor affords a wide range of adjustment, since thc ierounding material being large, this temperature-need sistance ofthe metallic conductor, spacing aindlongth not necessarily be high, as a very low final specific of the turns may all be adjusted so as toproduce the resistance will not be required. It will-be seen that 40 desired result. The path through theresistance of thc by making the conducting spiral of heavy, stiff mate- 95 second class from one turn of the metallic conductor rial the strength 0f the stick will be substantially into another isof comparatively large cross-section so that. creased. Various other methods ofconstructing this a very low final resistance of the material is not necesresistance unit will suggest themselves to one' skilled sary. This construction also makes it possible to add in the art. O f course, it is not essential that the spiral to the mechanical strength of the stick. l be on the inside of the tube, nor that a particular mate 100V In the accompanying sheet of drawings, I have shown rial, or the method of arranging the saine be used, the one embodiment of my invention for purposes of illusimportant feature being the intimate relationship be` tration but it should be understood that I do not limit tween the spiral conductor and a conductor 0f the SGC- the invention to the particular construction or arrangeond class whereby the latter short-Circuits the formel ment of parte shown or described, but consider my nupon increase of temperature. 105 ventlon as broad as the scope of the claims annexed to what I Claim as new and desire to Secure by Lei-,ters and fornlmg apart of thm alphcal'lonf Patent ofthe United States, is: l The smgle hgure of drawmg represents a' longltudmal 1. A resistance unit comprising a material having a neg- Sccton of a devl, embodylllg my myellllon- :il'vc temperature coeflicent, and a resistance conductor Referring'to the drawing, l is a stick'of resistance ,Olllbdded Uwln- 110 A resistance unit comprising a selfreducing resist roc'lueing resistance material having an electrical resist/ ance material, and a helical resistance conductor, the: :moc conductor embedded therein.

turns of said conductor being in electrical Contact with 6. A rosistnnvn unit comprising n molded stiel: of mate- 15 said material, l'iui having :1 negativo temperni'ure coeicient and 11 helical 3' A resistance unit cmnl'jrjsng a maten-u1 having anotan resiskmce conductor, the suvcossive turns of which are tive temperature comcent and n resistance conductor supported hy said sl'irlc :uni in electrical Contact therewith.

having a positive temperature coefficient embedded therein In wiLnws wiwi-co1', I have hereunto sut my hand this 4. A resistance unit Comprising :L stick of material huv- '35m' lli." E Nlwmhp", 'm05- ing a negative temperature coeficient und u helical resist- 1) \[1]:1QLL )[AVMILLAN, ance conductor, the successive turns of which are in elecwmmsscs: trical Contact with said stick. my mmx R UMH 5. A resistance unit comprising u molded stick of seillIlzLi-:N Oni-mur

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